Raster output scanning arrangement for a printing machine

Abstract

A laser system having a light source that transmits a first laser beam and a second laser beam along a first optical path and a second optical path, respectively, is provided. The laser system further includes a waveplate disposed adjacent the light source and the waveplate includes a polarization altering segment and a light transmissive segment, the segments being connected to one another. The polarization altering segment is disposed in the first optical path for altering the polarization of the first laser beam as it passes therethrough, and the light transmissive segment is disposed in the second optical path.

What is claimed is: 
     
       1. A laser system, comprising: means for transmitting a first laser beam and a second laser beam along a first optical path and a second optical path, respectively; and   a waveplate, disposed adjacent said transmitting means, including: a polarization altering segment, disposed in the first optical path, for altering the polarization of the first laser beam as the first laser beam passes therethrough, and   a light transmissive segment, connected to said altering segment and disposed in the second optical path, for transmitting the second laser beam therethrough.     
     
     
       2. The laser system of claim 1, wherein said transmitting means comprises a light source adapted for emitting a plurality of laser beams. 
     
     
       3. The laser system of claim 2, wherein said light source includes a first laser diode and a second laser diode for emitting the first and second laser beams, respectively. 
     
     
       4. The laser system of claim 1, wherein said waveplate further comprises a support layer upon which said segments are mounted. 
     
     
       5. The laser system of claim 1, wherein said polarization altering segment comprises a liquid crystal. 
     
     
       6. The laser system of claim 5, wherein said liquid crystal comprises a nematic phase type liquid crystal. 
     
     
       7. The laser system of claim 1, wherein said waveplate comprises a stretched polymer film. 
     
     
       8. The laser system of claim 1, in which the first and second laser beams comprise first and second wavelengths, respectively, with the respective magnitudes of the first and second wavelengths being substantially equal. 
     
     
       9. The laser system of claim 1, wherein said light transmissive segment alters the polarization of the second laser beam. 
     
     
       10. The laser system of claim 1, wherein the first laser beam is linearly, orthogonally polarized, prior to being transmitted through said waveplate, and is circularly polarized upon being transmitted through said waveplate. 
     
     
       11. The laser system of claim 1, further comprising a collimating lens, positioned adjacent said waveplate, for collimating the first and second laser beams. 
     
     
       12. The laser system of claim 11, wherein said waveplate is disposed intermediate of said light source and said collimating lens. 
     
     
       13. The laser system of claim 1, in which an angle of acceptance is defined by the first laser beam and a surface of said waveplate, with the angle of accetance having a range of at least 0°-20°. 
     
     
       14. The laser system of claim 1, in which said transmitting means emitts a third laser beam along a third optical path of transmission and said waveplate further comprises a third segment disposed in the third optical path, wherein said third segment alters the polarization of the third laser beam as the third laser beam passes therethrough. 
     
     
       15. A raster output scanning arrangement for a printing machine of the type having a photoreceptor, comprising: means for transmitting a first beam and second beam along a first optical path and second optical path, respectively; a waveplate disposed adjacent said transmitting means, including a polarization altering segment, disposed in the first optical path, for altering the polarization of the first laser beam as the first laser beam passes therethrough, and   a light transmissive segment, connected to said altering segment and disposed in the second optical path, for transmitting the second laser beam therethrough, wherein the the photoreceptor is positioned for receiving the first beam.     
     
     
       16. The raster output scanning arrangement of claim 15, wherein said altering segment comprises a liquid crystal. 
     
     
       17. The raster output scanning arrangement of claim 15, further comprising an optical filter, said optical filter being interposed between said waveplate and the photoreceptor for receiving the first and second beams, said optical filter being selective with respect to both wavelength and polarization, said optical filter reflecting the first beam and passing the second beam therethrough. 
     
     
       18. The raster output scanning arrangement of claim 17, wherein said optical filter comprises a liquid crystal cell. 
     
     
       19. The raster output scanning arrangement of claim 17, in which the printing machine includes a second photoreceptor and a set of reflective mirrors, wherein said optical filter interacts cooperatively with said set of mirrors for directing the first and second beams to the first photoreceptor and the second photoreceptor, respectively. 
     
     
       20. The raster output scanning arrangement of claim 15, wherein said light transmissive segment alters the polarization of the second beam. 
     
     
       21. The raster output scanning arrangement of claim 15, further comprising a collimating lens, positioned adjacent said waveplate, for collimating the first and second beams. 
     
     
       22. The raster output scanning arrangement of claim 21, wherein said waveplate is disposed intermediate of said light source and said collimating lens. 
     
     
       23. The raster output scanning arrangement of claim 17, further comprising a polygon mirror mounted for rotation about a central axis for simultaneously deflecting the first and second beams to said optical filter. 
     
     
       24. A raster output scanning arrangement for a printing machine of the type having a photoreceptor, comprising: means for transmitting a first beam and a second beam along a first optical path and a second optical path, respectively;   means for altering the polarization of the first beam;   means for deflecting the first and second beams into a third optical path; and   a single optical filter disposed in the third optical path, said single optical filter being selective with respect to both wavelength and polarization and being configured in a manner that permits the first beam to be reflected and the second beam to be passed through said single optical filter.   
     
     
       25. The raster output scanning arrangement of claim 24, wherein each of the first and second beams is orthogonally polarized. 
     
     
       26. The raster output scanning arrangement of claim 24, wherein said single optical filter comprises a liquid crystal cell. 
     
     
       27. The raster output scanning arrangement of claim 26, wherein said liquid crystal cell is characterized by an adjustable pitch with the wavelength selectivity being manipulated by adjusting the pitch of said liquid crystal cell. 
     
     
       28. The raster output scanning arrangement of claim 26, wherein said liquid crystal is characterized by a cholesteric liquid crystal structure having a selected direction with the polarization of the first beam being manipulated by selecting the direction of said cholesteric liquid crystal structure. 
     
     
       29. The raster output scanning arrangement of claim 24, in which the printing machine includes a second photoreceptor and a set of reflective mirrors, wherein said single optical filter interacts cooperatively with said set of mirrors for directing the first and second beams to the first photoreceptor and the second photoreceptor, respectively. 
     
     
       30. The raster output scanning arrangement of claim 24, in which said light source is adapted to emit a third beam, said deflecting means deflects the third beam into the third optical path, said separating means separates the third beam from the first and second beams, and the third beam passes through said optical filter, further comprising: a second optical filter spaced from said first optical filter, said second optical filter being adapted to receive the second and third beams, said second optical filter being selective with respect to both wavelength and polarization and being adapted to reflect the second beam and transmit the third beam therethrough.   
     
     
       31. The raster output scanning arrangement of claim 30, wherein said second optical filter comprises a liquid crystal cell.